Device for pouring liquefied gas



Jan. 10, 1967 s. FEUERSTEIN DEVICE FOR POURING LIQUEFIED GA3 Filed Aug. 23, 1965 .2g/g 2016,14... w?

United States Patent Office 3,296,809 DEVICE FOR POURING LlQUEFIlED GAS Seymour Feuerstein, Los Angeles, Calif., assigner to The Aerospace Corporation, Los Angeles, Calif., a corporation of California Filed Aug. 23, 1965, Ser. No. 481,844 6 Claims. (Cl. 62-55) This invention relates to a device providing the rapid and lowloss removal of liquefied gas from a pressurized vessel to an open container.

Following conventional practice, liquefied gases, as oxygen and carbon dioxide, are stored in pressurized tanks to facilitate transporting and handling and to prevent loss due to evaporation. When it is desired to fill an open Dewar or similar vessel with the liquefied gas a small diameter tube is attached to the valved outlet of the pressure tank. On opening the valve the liquid gas is ejected from the tank outwardly through the tube. Being suddenly relieved of its confining pressure a portion of the gas vigorously boils and evaporates within the tube. As it boils ofi a substantial quantity of mist or fog is created. Although a portion of the mist consists of condensed atmospheric moisture, a greater portion of it is made up of the vapor of the previously liquefied gas.

The present invention has as its primary purpose the reduction in the loss of the liquefied gas through boil-ofi. In accomplishing its purpose there is provided both econ omy and convenience in the near elimination of the massive clouds of fog which heretofore accompanied the pouring operation. v

The purpose of this invention is achieved through the provision of a substantially closed expansion chamber serving to confine the boiled-off gas. Within the charnber is provided a condensing media which acts to recondense the gas and to collect the mist entrained in the evaporated gas.

The invention consists essentially of an insulated cylindric expansion chamber substantially filled with a loosely packed fibrous material such as stainless steel wool. Within the chamber is an open ended swirl ring into which the liquefied gas is initially admitted. The liquefied gas from the main pressurized container is led through a short length of tubing tangentially into the swirl ring.

The upper end of the expansion chamber is closed by a perforated cap which permits the exhaust of the small portion of the liquefied gas that has boiled off and which does not get recondensed on the fibrous packing. The lower end of the expansion chamber is closed by a cap having a short outlet spout attached to it.

In the pouring operation in which the present invention is utilized, the initial liquefied gas flow immediately reduces the fibrous wool to the temperature of the gas. In this manner the wool becomes an ideal condenser and filter for the gaseous mist. The condensed gas drains to the bottom of the expansion chamber where it joins the main liquid flow through the outlet tube. This outfiow is gentle in contrast with the turbulent fog bound flow that was characteristic of the pouring operation prior to my invention.

It is reasonably estimated that by the use of the present invention the rate of fiow of liquefied gas into a Dewar vessel can be doubled while the loss of gas through evaporation is reduced one-half.

These and additional features and advantages of the invention will become apparent from the following dey Maasai Patented Jan. l0, 1957 Referring to the drawing, the invention is shown as having an internally threaded coupling nut 12 which attaches to the valved outlet of a pressurized liquefied gas container (not shown). Leading away from the nut 12 is a short length of tubing 14 which passes through the wall and into the interior of the expansion chamber 18. This chamber 18 is a long cylindrical member preferably having walls formed of a good heat insulating material.

There is suspended centrally within chamber 18 an annular swirl ring 22 affixed to the end of the inlet line 14. As seen in the drawing, the inlet line 14 intersects the swirl ring 22 at an angle such as to Acause the liquefied gas to enter the swirl ring 22 tangentially. Thus the entering fluid flow is caused to swirl within the ring 20 to facilitate the dissipation of its energy. The swirl ring 22 further assures a more uniform flow of the evaporated gas through the interior of the expansion chamber 18.

Within chamber 18, including the interior of swirl ring 22, there is loosely packed a mass of a fibrous material 24. For better eliiciency the material 24 should be stainless steel wool or other non-absorbent and non-corroding material. The fibrous material 24 is employed since it provides an extremely large surface area on which the evolving mist can collect and be condensed. During the pouring it will be obvious that the temperature of the material 24 almost immediately is reduced to the temperature of the liquefied gas. The accumulated condensate gravitates to the bottom of chamber 18 and thereby further provides an absorbent bath for the expanding mist of gas. The action of the fibrous material 24 and the condensate is thus seen to be cumulative.

At its top, the expansion chamber 18 is fitted with a perforated cap 28 which vents to the atmosphere. From the lower end of chamber 18 extends an outfiow tube 26 fitted into a mating hole in the bottom plate 30. Both the cap 28 and the plate 30 are formed of insulating material as are the sidewalls of the chamber 18.

As a precautionary measure a filter screen 32 is placed across the bottom plate 30 and the opening to exit tube 26. This screen 32 will prevent any loose fibers of the steel wool 24 from passing out of the device with the liquefied gas.

With the present construction, all the boilofi from the liquefied gas is caused to pass through a large volume of the matted fibrous material 24. In this manner a high percentage of this mist or fog is recondensed. It will be apparent then that the configuration of the expansion chamber 18 and the swirl ring (or baffle) 22 can be varied with respect to each other to provide other forms of the invention.

While only a single form of my invention is described it will be obvious that it is capable of modification and change within the scope of the following claims.

I claim:

1. A device for the removal of liquefied gas from a zone of high pressure to a zone of reduced pressure cornprising:

an expansion chamber having an upper cap and a lower closure cap;

vent means in the upper cap freely communicating the interior of the expansion chamber with the atmosphere;

an inlet duct discharging liquefied gas from the zone of high pressure into the expansion chamber at a region remote from the vented cap;

liquid outlet means at the lower end of the chamber;

a fibrous material loosely packed within and substantially filling the interior of the expansion chamber; and

baflie means within the expansion chamber dispersing the liquefied gas and its vapors discharged from the inlet duct.

2. A device as defined in claim 1 wherein the bale means comprises a swirl ring centrally within the expansion chamber and wherein the inlet duct discharges the liquefied gas tangentially to the interior of the swirl ring.

3. A device as defined in claim 1 wherein the liquid outlet means includes a duct receiving fluid through an opening in the lower closure cap; and

filter screen means across the opening in the lower closure cap precluding the passage therethrough of any of the fibrous material.

4. A device as defined in claim 1 wherein the fibrous material is non-absorbent, non-corroding steel wool.

5. A device as defined in claim 1 wherein the expansion chamber, the upper cap and lower cap are formed of materials having a low thermal conductivity.

6. A device as defined in claim 1 wherein the vent means in the upper cap includes a plurality of perforations to 5 permit the ready escape of the vapors from the expansion chamber.

References Cited by the Examiner UNITED STATES PATENTS 10 3,044,270 7/ 1962 Biever 62-55 3,130,555 4/ 1964 Haettinger 62-55 3,201,947 8/1965 Post et al. 62-55 3,206,939 9/ 1965 Wilson 62-55 LLOYD L. KING, Primary Examiner. 

1. A DEVICE FOR THE REMOVAL OF LIQUEFIED GAS FROM A ZONE OF HIGH PRESSURE TO A ZONE OF REDUCED PRESSURE COMPRISING: AN EXPANSION CHAMBER HAVING AN UPPER CAP AND A LOWER CLOSURE CAP; VENT MEANS IN THE UPPER CAP FREELY COMMUNICATING THE INTERIOR OF THE EXPANSION CHAMBER WITH THE ATMOSPHERE; AN INLET DUCT DISCHARGING LIQUEFIED GAS FROM THE ZONE OF HIGH PRESSURE INTO THE EXPANSION CHAMBER AT A REGION REMOTE FROM THE VENTED CAP; LIQUID OUTLET MEANS AT THE LOWER END OF THE CHAMBER; A FIBROUS MATERIAL LOOSELY PACKED WITHIN AND SUBSTANTIALLY FILLING THE INTERIOR OF THE EXPANSION CHAMBER; AND BAFFLE MEANS WITHIN THE EXPANSION CHAMBER DISPERSING THE LIQUEFIED GAS AND ITS VAPORS DISCHARGED FROM THE INLET DUCT. 